Improve Informativeness of Success and Error Messages

[supitsdu]

The current messages displayed by clipper are somewhat basic. We can improve the user experience by making the messages more informative.

For example:

• Success: Instead of "Clipboard updated successfully", specify the amount of data copied (e.g., "Copied 1024 bytes to clipboard").
• Error: Provide more context about the cause of the error (e.g., "Error reading file 'example.txt': Permission denied").

Tasks:

1. Review and revise the messages displayed in the main function.
2. Consider using different colors or formatting to distinguish between success and error messages.